JPH0667736B2 - Power steering used in vehicles - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power steering used in a vehicle that is speed and load sensitive and is a type of delay compensation.

BACKGROUND ART In general, speed-sensitive power steering has been widely used in automobiles, but with this type of power steering, the operating force is changed according to the load, and there is a difference in operational feeling and steering stability. In addition, regarding delay correction,
The current situation is that no special consideration has been given.

In such a power steering system, the hydraulic pump and the power cylinder have been designed so as to ensure the stationary set-up capability when the vehicle is stopped and the steering force that is required when running at extremely low speeds. In addition, even in high-speed running where a large steering force is not required, a large load is applied to the engine, and the fuel consumption rate tends to be reduced.

Further, a power steering apparatus which utilizes a supplementary cylinder to adapt a steering force to a vehicle speed is disclosed in Japanese Utility Model Laid-Open No. 60-157475.

However, in this power steering apparatus, the operation delay is caused because the correction of the turning delay is not taken into consideration. Especially, in the power steering device,
Since the pressure oil passes through the power steering and is directionally controlled by the on-off valve to be supplied to the auxiliary cylinder, the delay delay correction by the auxiliary cylinder is disadvantageous.

Objects and Problems of the Invention The objects and problems of the present invention are to suppress the enlargement of the hydraulic pump and the enlargement of the pressure receiving area of the piston in the power cylinder, suppress the wasteful consumption of engine generated power, and reduce the fuel consumption rate of the engine The steering force is appropriately changed according to the load during traveling, the stationary steering force is lightened when the vehicle is stopped, the steering wheel turning delay, that is, the steering operation delay is prevented, and steering fatigue is reduced. The purpose is to provide power steering used in vehicles where it is used.

SUMMARY OF THE INVENTION FOR OBJECTS AND PROBLEMS In relation to the above objects and problems, the power steering used in the vehicle of the present invention is an integral structure of a main booster and an auxiliary booster. Dual cylinder type power cylinder that steers a pair of front wheel shafts that are swingably connected to each other, a manual control valve that is arranged in the main hydraulic pipe that connects the main booster to the hydraulic pump, and its auxiliary An electromagnetic directional control valve arranged in an auxiliary hydraulic pipe connecting the booster to its hydraulic pump, a vehicle speed sensor,
The steering sensor and a controller for controlling the current flowing through the electromagnetic directional control valve in response to the signal of the load sensor are included, and the vehicle speed sensor, the steering sensor, and the load sensor detect the running state of the vehicle. , The steering wheel operation and load increase / decrease are promptly judged by the controller, the current flowing through the electromagnetic directional control valve is controlled, the pressure oil is quickly supplied to the auxiliary booster, and the steering force of the main booster is supplied to the auxiliary booster. In addition, the auxiliary booster corrects the delay of the main booster, that is, the operation delay.

Description of Specific Examples Specific examples of the power steering used in the vehicle of the present invention will be described below with reference to the drawings.

The figure shows a tenth embodiment of the power steering used in the vehicle of the present invention applied to a cab-over type truck.

This power steering 10 includes a knuckle (not shown) and a king wheel at both ends of a front axle (not shown) arranged in front of a chassis frame (not shown) of the truck.
A double sector shaft 35, a pitman arm 57, a drag link 58, and a knuckle are connected to a pair of front wheel shafts 60 and 61 that are swingably connected via a pin (not shown).
Front wheels 62 and 63 that are connected via an arm 59 and rotatably supported by the front wheel shafts 60 and 61 are configured to be operable.The front wheels 62 and 63 are manufactured as an integral structure of the main booster 11 and the auxiliary booster 12. Dual steering wheel shaft 60,61
Cylinder type power cylinder, manual control valve 14 arranged in main hydraulic pipes 20 and 21 connecting the main booster 11 to the hydraulic pump 13, and auxiliary hydraulic pipe connecting the auxiliary booster 12 to the hydraulic pump 13. Electromagnetic directional control valve 15 arranged on 22, 23, vehicle speed sensor 24, steering sensor 2
5 and a controller 16 for controlling the current flowing through the electromagnetic directional control valve 15 in response to the signal of the load sensor 26, a flow control valve 17, a control valve bypass 18, and an oil reservoir 19. Composed of.

The dual cylinder type power cylinder has a steering wheel 55 via a steering shaft 56.
It incorporates its manual control valve 14 which is operated by switching, and integrates its auxiliary booster 12 with its main booster 11 which includes a steering gear box (not shown) to enable manual steering. Manufactured.

Its main booster 11 is its manual control valve
It is possible to reciprocally slide in the main cylinder body 30 that incorporates 14 and that integrally manufactures the sub-cylinder body 36 of the auxiliary booster 12, and the cylinder bore 31 of the main cylinder body 30. The piston 34 is fitted into the cylinder bore 31, and forms a pair of cylinder chambers 32, 33 in the cylinder bore 31, and is engaged with the piston 34.
It is composed of a double sector shaft 35 that transmits the force and movement of the piston 34 to the pitman arm 57.

Further, the main booster 11 connects the oil port (not shown) of one cylinder chamber 32 and the cylinder port (not shown) of the manual control valve 14 corresponding to the oil port. Communication passage (not shown), and an oil port (not shown) of the other cylinder chamber 33 and a cylinder port (not shown) of the manual control valve 14 corresponding to the oil port. A communication passage (not shown) for communicating with the main hydraulic pipes 20, 21,
That is, the cylinder chambers 32, 33 are configured to be switchably connectable to the supply-side and return-side hydraulic pipes 20, 21.

With its main booster 11 so configured, the force and movement of its piston 34 is reduced to its double sector shaft.
35, the pitman arm 57, the drag link 58 and the knuckle arm 59 to the front wheels 62, 63, and thus the main booster 11 thereof has its front wheels 62, 63.
Steer.

The auxiliary booster 12 can slide back and forth within the sub cylinder body 36 integrally formed with the main cylinder body 30 of the main booster 11 and the cylinder bore 37 of the sub cylinder body 36. To form a pair of cylinder chambers 38, 39 inside the cylinder bore 37,
It is composed of a piston 40 meshed with the double sector shaft 35.

Further, the auxiliary booster 12 is provided with oil ports 41 and 42 in the sub cylinder body 36 thereof, and the oil ports 41 and 42 are connected to the hydraulic pump 13 and the oil reservoir 1 respectively.
9 is connected to the auxiliary hydraulic pipes 22 and 23. Of course, the auxiliary hydraulic pipes 22 and 23 are
23, which is connected to the main hydraulic pipes 20 and 21, that is, the supply-side and return-side hydraulic pipes 20 and 21.

The main booster 11 and the auxiliary booster 12 are each manufactured so as to obtain an output that is half of the output required during stationary operation or extremely low speed running.

The hydraulic pump 13 is operated by a diesel engine (not shown) mounted on the truck, and the pump of the manual control valve 14 is used to supply pressure oil to the main booster 11 and the auxiliary booster 12. · Its supply-side hydraulic piping connecting its oil reservoir 19 to port 44
It is arranged at 20 and sucks up and pressurizes the oil in the oil reservoir 19 to obtain a discharge amount of the pressure oil which is almost proportional to the rotation speed of the diesel engine. Of course, this hydraulic pump 13 is manufactured in the same configuration as the hydraulic pump used for the existing power steering, and therefore its explanation is omitted.

The manual control valve 14 is configured as a hydraulic reaction force type spool valve, is incorporated in the main cylinder body 30 of the main booster 11, and is connected to the steering shaft 56 of the input shaft. A spool (not shown) is connected to a spool shaft (not shown) fixed to the pump (not shown), the steering wheel 55 is operated to switch valves through the steering shaft 56, and the pump is operated.・ Port 44 and tank port 45 with their supply and return hydraulic lines 20,21
The pressure oil discharged from the hydraulic pump 13 and flow-controlled by the flow control valve 17 is directionally controlled and supplied to the main booster 11, and the pressure oil worked by the main booster 11 is connected. Direction control the hydraulic pump
Return the pressure oil to its oil reservoir 19, which is the suction side of 13.

The manual control valve 14 includes a valve body 43 having a valve bore (not shown), and a reciprocally slidable arrangement in the valve bore. A pair of reaction chambers are provided at both ends of the valve bore. The valve body 43 is formed with a spool (not shown) forming a valve (not shown).
Pump port 44 and tank port 4 open to the bore
5, multiple cylinder ports (not shown) are formed.

The valve body 43 is located in the reaction chamber and forms a pair of reaction ports (not shown) in the valve body 43, and the reaction port is connected to a reaction communication passage (not shown). ), And a throttle (not shown) is arranged in the reaction communication passage.

The spool switches connection of its pump port 44 to its cylinder ports and its cylinder ports to its tank port 45 as it slides back and forth within its valve bore. To be possible.

As the spool slides back and forth in the valve bore, the pump port 44 and tank
A pair of communication ports (not shown) are provided for switching and connecting the port 45 to the reaction chamber.

In the manual control valve 14 where such a structure is adopted, the pressure oil discharged from the hydraulic pump 13 and adjusted in flow rate by the flow control valve 17 is used for the cylinder chamber 32 of the main booster 11. , 33, its pump port 44 is its supply hydraulic line 20 and its outlet of the flow control valve 17.
53, and its tank port 45 is connected to its oil reservoir 19 by its return hydraulic line 21, respectively.

The electromagnetic directional control valve 15 includes a valve body 46, a spool (not shown) that is reciprocally slidably disposed in a valve bore (not shown) of the valve body 46, and an electromagnetic valve that moves the spool. A spool type four-way control valve including a coil (not shown) is used and its power steering 10
In the hydraulic circuit of 1, the auxiliary hydraulic pipes 22 and 23 are arranged, and in the electric circuit of the power steering 10, it is electrically connected to the controller 16.

The electromagnetic directional control valve 15 is connected to the controller 16
When a current controlled by excites the magnet coil, the magnet coil causes the spool to move, opening the valve bore in place with the pump port 47,
Cylinder ports 48, 49 and tank port 50 are switched and connected, and their hydraulic pump 13 to its auxiliary booster 12
And directs the pressure oil flowing from the auxiliary booster 12 to the oil reservoir 19.

The controller 16 electrically connects the input side to the vehicle speed sensor 24, the steering sensor 25, and the load sensor 26, and electrically connects the output side to the electromagnetic coil of the electromagnetic directional control valve 15 to determine the vehicle speed. In response to the signals from the sensor 24, the steering sensor 25, and the load sensor 26, the current flowing through the electromagnetic coil is controlled, and the electromagnetic directional control valve 15 is operated by port switching connection operation. It is about to give a delay correction characteristic to the power steering 10, and is mainly composed of an input and output circuit, a memory circuit, an arithmetic circuit, a control circuit and a power supply circuit,
The power circuit is the truck battery (not shown)
Are shared.

In order to give the power steering 10 its speed-responsive characteristic, the controller 16 responds to the signals from the vehicle speed sensor 24 and the load sensor 26 at a low speed running up to a predetermined speed, and the main booster 11 Is operated at full power, and at the same time, its auxiliary booster 12 is moved at a relatively high power to lighten steering of the steering wheel, that is, the steering wheel 55, and when traveling over a predetermined speed. , The main booster is moved in the full output state, and at the same time, the auxiliary booster 12 is moved in the gradually reduced output state according to the traveling speed to make the steering wheel 15 steeper.

Further, the controller 16 provides the load steering characteristic to the power steering 10 in response to the signals from the vehicle speed sensor 24 and the load sensor 26 at the time of the stationary operation. Move both 12 and 12 to lighten the steering wheel 55,
Further, when traveling, only the main booster 11 is moved to prevent the steering wheel 55 from being excessively lightly steered.

Further, the controller 16 responds to signals from the vehicle speed sensor 24 and the steering sensor 25 in order to give the power steering 10 the cut-delay correction characteristic of the main booster 11. First, the auxiliary booster 12 is moved more than the main booster 11 in response to the steering operation direction, in other words, the rotation direction of the steering wheel 55. The main booster 11 suppresses delay.

The vehicle speed sensor 24 connected to the input side of the controller 16 detects the traveling speed of the truck, is arranged on the output shaft of a transmission (not shown) mounted on the truck, and also controls the steering. The sensor 25 is
The steering wheel 55, that is, the one that detects the rotation direction, rotation speed, and rotation angle of the steering shaft 56, is arranged on the steering shaft 56 at a predetermined position, and the load sensor 26 is A pressure sensor, which is arranged in the supply-side hydraulic pipe 20 that connects the main booster 11 to the hydraulic pump 13,
The pressure of the pressure oil discharged from the hydraulic pump 13 corresponding to the load is sensed.

The flow control valve 17 is connected to the hydraulic pump 13 and the oil reservoir 19 in the hydraulic circuit.
Is located in the supply side hydraulic line 20 that connects the manual control valve 14 to the control valve
A bypass 18 connects to the return hydraulic line 21.

The flow control valve 17 has an inlet 52 connected to the discharge side of the hydraulic pump 13 and an outlet 5 connected to the pump port 44 of the manual control valve 14.
3, and the return port 54 connected to the return side hydraulic pipe 21
Pressure oil sent to the inlet 52 of the valve casing 51, and an oil return control spool (not shown) that is reciprocally slidably disposed in the valve casing 51. Is adjusted so that a predetermined flow rate is sent to the outlet 53, and the surplus flow rate of the pressure oil is returned from the return port 54 to the oil reservoir 19 via the control valve bypass 18.

Of course, the flow control valve 17 is manufactured in the same structure as the flow control valve used for the existing power steering, and the detailed description of the structure will be omitted.

Next, the operation of the power steering 10 described above will be described with reference to the running state of the truck. Since the diesel engine is operating, the hydraulic pump 13
Is operated, the flow rate of the pressure oil discharged from the hydraulic pump 13 is adjusted by the flow control valve 17, and a predetermined flow rate of the pressure oil flows through the supply side hydraulic pipes 20 and 22 to control it. Routed to pump ports 44,47 of valves 14,15.

And the pressure oil sent to the pump ports 44, 47 is
When the steering wheel 55 is placed in the neutral position, the tank
Returned to its oil reservoir 19 through ports 45,50.

At the same time, the controller 16 is the vehicle speed sensor.
Signals from the steering sensor 25, the steering sensor 25, and the pressure sensor 26 are input to control the current flowing in the electromagnetic coil of the electromagnetic directional control valve 15 so that the electromagnetic directional control valve 15 is switched and connected.

Now, when the truck is full of luggage and traveling on the road at a low speed up to a predetermined speed, its controller 16
But its vehicle speed sensor 24, steering sensor 25 and pressure sensor
Input the signal from 26, calculate according to the input signal, determine the output current, and output the output current to the electromagnetic directional control valve 15
Since it is applied to the electromagnetic coil, the electromagnetic coil is excited,
In the electromagnetic directional control valve 15, the spool corresponds to the steering of the steering wheel 55, that is, the rotation direction, the rotation speed, and the rotation angle.
It is slid into the valve bore of body 46.

Therefore, the main booster 11 is discharged from the hydraulic pump 13, and the pressure oil whose flow rate is adjusted by the flow control valve 17 is directionally controlled by the manual control valve 14, is supplied and is operated, and is simultaneously operated. In addition, the auxiliary booster 12 is discharged from the hydraulic pump 13, and the pressure oil whose flow rate is adjusted by the flow control valve 17 is directionally controlled by the electromagnetic directional control valve 15 and is supplied and moved. The wheels 62 and 63 are the double sector shaft 35, the pitman arm 57, and the drag link 58.
And its main booster 11 via knuckle arm 59
And it is steered by the auxiliary booster 12.

In this way, the steering force of the main booster 11 is supplemented by the auxiliary booster 12, so that the steering is performed with a small operation force. Of course, the controller 16 calculates the output current for the correction of the delay in response to the signals from the vehicle speed sensor 24 and the steering sensor 25, and sends the output current to the electromagnetic coil of the electromagnetic directional control valve 15. , The electromagnetic directional control valve 15 is operated to advance the main booster 11 further than the main booster 11 at the start of the main booster 11 and the start of the delay operation, and the auxiliary booster 12 is momentarily moved. The turning delay of the wheel 55, that is, the steering operation delay is suppressed.

Further, when the truck is driven at a high speed, which is a speed exceeding a predetermined speed, the controller 16 inputs signals from the vehicle speed sensor 24, the steering sensor 25, and the pressure sensor 26. , And the output current is passed through the electromagnetic coil of the electromagnetic directional control valve 15, so that the electromagnetic coil is excited and the spool of the electromagnetic directional control valve 15 has its spool
Slid into 46 valve bores and its pump port 47
To its tank port 50 and, at the same time, its cylinder ports 48, 49 to each other.

Therefore, the auxiliary booster 12 is placed in the empty motion state,
The main booster 11 is discharged from the hydraulic pump 13, and the pressure oil whose flow rate is adjusted by the flow control valve 17 is directionally controlled by the manual control valve 14 and is supplied and moved to the front wheel. 62 and 63 are the double sector shaft 35, Pitman arm 5
7, steered by its main booster 11 via a drag link 58 and a knuckle arm 59.

In this way, since the steering is performed only by the main booster 11, a relatively large operating force is required for the steering during the high speed traveling, and the traveling stability is improved.

Even in this high-speed traveling, the controller 16 responds to the signals from the vehicle speed sensor 24 and the steering sensor 25,
The output current for the cut-off delay correction is calculated, the output current is caused to flow through the electromagnetic coil of the electromagnetic directional control valve 15, the electromagnetic directional control valve 15 is operated, and the main booster is turned on and off. First, the auxiliary booster 12 is moved momentarily by advancing it from the main booster 11 to suppress the steering wheel 55 from being cut off, that is, steering operation delay.

Furthermore, when the truck is stationary, the output current is calculated according to the signals from the vehicle speed sensor 24 and the pressure sensor 26, and the output current is passed through the electromagnetic coil of the electromagnetic directional control valve 15, The electromagnetic directional control valve 15 is switched to operate the auxiliary booster 12.

Therefore, both its main and auxiliary boosters 11, 12 move and its front wheels 62, 63 have their main and auxiliary boosters 11, 12,
Steered at 12, the staging is very light.

As will be apparent from the specific embodiments of the present invention described above with reference to the drawings, those having ordinary skill in the art to which the present invention pertains,
The subject matter of this invention is readily embodied in other aspects which are derived from the nature and substance of the invention and which are objectively admitted to incorporate them. Of course, the contents of the present invention are essential to the establishment of the invention in accordance with the problems of the invention.

Benefits of the Invention As will be understood from the above, the power steering used in the vehicle of the present invention comprises a pair of front wheel axles that are swingably connected to both ends of the front axle with an integral structure of a main booster and an auxiliary booster. Dual-cylinder power cylinder that steers the vehicle, a manual control valve that is placed on the main hydraulic line that connects the main booster to the hydraulic pump, and an auxiliary hydraulic line that connects the auxiliary booster to the hydraulic pump Electromagnetic directional control valve, vehicle speed sensor,
The current flowing through the electromagnetic directional control valve is controlled according to the signals of the steering sensor and the load sensor to cause the auxiliary booster to supplement the steering force of the main booster, and the auxiliary booster also delays the operation of the main booster. Since the power steering used in the vehicle of the present invention is configured to include a controller for correction, the vehicle speed sensor, steering sensor, and load sensor detect the traveling state of the vehicle, and handle operation and load The controller quickly determines the increase / decrease, controls the current flowing through the electromagnetic directional control valve, and moves the auxiliary booster in a relatively large output state at low output speeds up to a predetermined speed to achieve the full output state. The steering force of the main booster, which is driven by, is supplemented with the steering force of the auxiliary booster, and at the same time, the delay due to the main booster is delayed. Is the correction to the auxiliary booster, also,
When traveling over a predetermined speed, the auxiliary booster is moved in a gradually smaller output state according to the traveling speed, and the slight boosting force of the auxiliary booster is supplemented to the steering force of the main booster operated at all output states. That is, especially at high speeds, only the main booster is moved, and at the same time, the delay caused by the main booster is corrected by the auxiliary booster, so that at low speeds, the steering wheel delays, so-called steering. The operation delay is avoided and the steering is performed with a small steering force. Also, in the middle / high speed traveling, at the same time, the operation delay of the steering is avoided, and a relatively large steering force is required for steering, and stable traveling is achieved. Is improved, and
During these travelings, the pressure oil is directionally controlled by the electromagnetic directional control valve and supplied to the auxiliary booster without passing through the main booster, so that the increase in resistance loss is suppressed and the delay boost correction by the auxiliary booster is advantageous. Furthermore, in the case of stationary operation, both the main and auxiliary boosters are moved, steering is performed very lightly, and further, as the main and auxiliary boosters are moved in this manner, the hydraulic pressure is increased. The size of the pump and the pressure receiving area of the piston in the power cylinder can be suppressed from increasing, the wasteful consumption of engine generated power can be suppressed, the fuel consumption rate of the engine can be improved, and even when traveling, depending on the load. The steering force can be changed appropriately, and the driver's fatigue due to steering is reduced, and in particular, the applicability to large vehicles is improved. It is very useful and practical Te.

[Brief description of drawings]

The figure is a schematic diagram showing a specific example of the power steering used in the vehicle of the present invention applied to a truck. 11 …… Main booster, 12 …… Auxiliary booster, 13 …… Hydraulic pump, 14 …… Manual control valve, 15 …… Electromagnetic directional control valve, 16 …… Controller.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location B62D 123: 00 (56) References JP 60-197467 (JP, A) JP 59- 118571 (JP, A) JP 57-186579 (JP, A) JP 57-26052 (JP, A) JP 61-166773 (JP, A) JP 60-143177 (JP, A) JP-A-60-143178 (JP, A) Actual opening 60-157475 (JP, U) Actual opening 59-109573 (JP, U) Actual opening Sho-55-85967 (JP, U)

Claims (1)

[Claims] 1. A dual cylinder type power cylinder for steering a pair of front wheel shafts swingably connected to both ends of a front axle with an integrated structure of a main booster and an auxiliary booster, and the main booster for a hydraulic pump. Manual control valve located on the main hydraulic line to be connected, electromagnetic directional control valve located on the auxiliary hydraulic line connecting the auxiliary booster to the hydraulic pump, and signals from the vehicle speed sensor, steering sensor, and load sensor According to the control of the current flowing through the electromagnetic directional control valve to make the auxiliary booster supplement the steering force of the main booster,
A power steering used in a vehicle that includes a controller that causes the auxiliary booster to compensate for the operational delay of the main booster.